Abstract:
Objective Biological characteristics of the pathogen causing sour rot disease on Pseudostellaria heterophylla were studied.
Method Diameters of Geotrichum candidum FJAT-32652 colonies on culture medium under varied temperature, pH, light, and carbon and nitrogen sources were measured to determine the optimal growth conditions for the pathogen. Lethal temperature and time of the spores were determined, and spore germination observed under a microscope.
Results The optimum growth conditions for the pathogen included 30 ℃, pH 6, maltose, lactose, and glucose for carbon source, and ammonium sulfate for nitrogen source. Light exposure had no significant effect on the mycelial growth. Lethality occurred by submerging the spores in 65 ℃ hot water for 10 min. Spore germination started 3 h after incubation, and mycelia became visible in 9 h. Schizogamy was the reproduction mode of the pathogen.
Conclusion The biological characteristics of G. candidum were determined for subsequent studies on the sour rot disease of P. heterophylla.